This human Embryonic Stem (hES) Cell Training and Culture Core has two objectives. The first is to provide centralized hES culture support to all projects; the second is to broadly support hES cell work in our geographic region (Texas/Gulf Coast/South-west) by sponsoring a hES cell training program, to facilitate adoption of the technology among a larger number of laboratories. For the first objective, we will provide quality-tested reagents, such as lot-tested media and mouse embryonic fibroblasts (MEF) to all projects. We will also provide cultures of WA01 (H1)and WA09 (H9)cells to project investigators on a routine basis, and large-scale cultures of these lines upon request. We will ensure the hES provided to our investigators are high quality through routine testing for sterility, pluripotency, and genetic stability. For the second objective, we will offer a hES Training workshop every other month. This workshop will be an intensive week-long hands-on training in small groups with highly experienced hES workers. Training will include all basic hES-related technologies, such as MEF preparation and quality testing, hES culture and quality analysis, teratoma formation, and EB differentiation. In addition, an extended workshop will be offered annually that will include strategies for genetic modification. This workshop will be taught in collaboration with the Genetic Modification Core (Core C). By centralizing these efforts of hES training and culture, we expect to ensure high quality hES culture for our investigators, as well as dissemination of the technology throughout the Texas Medical Center and larger geographic region.